Brussels’ Zaventem international airport has been paralyzed by an electrical outage, leaving crowds of passengers gathered outside the airport unable to enter. Although power has since been restored, the interruption in flights has caused many delays.

The power outage occurred about 5:00am local time, Belgian Bruzz news reported.

In a brief statement, Zaventem authorities confirmed that a power outage had been responsible for the interruption in service at the airport.

“This morning a power outage occurred at Brussels Airport. Systems are running again. Passengers are expected in time for their flight. We apologize for the inconvenience,” the airport said in a statement.

Brussels Airport encountered this morning a power outage. Systems are running again.